Central Venous-to-Arterial CO 2 Gap Is a Useful Parameter in Monitoring Hypovolemia-Caused Altered Oxygen Balance: Animal Study

Monitoring hypovolemia is an everyday challenge in critical care, with no consensus on the best indicator or what is the clinically relevant level of hypovolemia. The aim of this experiment was to determine how central venous oxygen saturation (ScvO 2 ) and central venous-to-arterial carbon dioxide difference (CO 2 gap) reflect hypovolemia-caused changes in the balance of oxygen delivery and consumption. Anesthetized, ventilated Vietnamese minipigs ( = 10) were given a bolus followed by a continuous infusion of furosemide. At baseline and then in five stages hemodynamic, microcirculatory measurements and blood gas analysis were performed. Oxygen extraction increased significantly, which was accompanied by a significant drop in ScvO 2 and a significant increase in CO 2 gap. There was a significant negative correlation between oxygen extraction and ScvO 2 and significant positive correlation between oxygen extraction and CO 2 gap. Taking ScvO 2 < 73% and CO 2 gap >6 mmHg values together to predict an oxygen extraction >30%, the positive predictive value is 100%; negative predicted value is 72%. Microcirculatory parameters, capillary perfusion rate and red blood cell velocity, decreased significantly over time. Similar changes were not observed in the sham group. Our data suggest that ScvO 2 < 73% and CO 2 gap >6 mmHg can be complementary tools in detecting hypovolemiacaused imbalance of oxygen extraction

Epidemiology of acute kidney injury in Hungarian intensive care units: a multicenter, prospective, observational study

<p>Abstract</p> <p>Background</p> <p>Despite the substantial progress in the quality of critical care, the incidence and mortality of acute kidney injury (AKI) continues to rise during hospital admissions. We conducted a national, multicenter, prospective, epidemiological survey to evaluate the importance of AKI in intensive care units (ICUs) in Hungary. The objectives of this study were to determine the incidence of AKI in ICU patients; to characterize the differences in aetiology, illness severity and clinical practice; and to determine the influencing factors of the development of AKI and the patients' outcomes.</p> <p>Methods</p> <p>We analysed the demographic, morbidity, treatment modality and outcome data of patients (n = 459) admitted to ICUs between October 1^st, 2009 and November 30^th, 2009 using a prospectively filled in electronic survey form in 7 representative ICUs.</p> <p>Results</p> <p>The major reason for ICU admission was surgical in 64.3% of patients and medical in the remaining 35.7%. One-hundred-twelve patients (24.4%) had AKI. By AKIN criteria 11.5% had Stage 1, 5.4% had Stage 2 and 7.4% had Stage 3. In 44.0% of patients, AKI was associated with septic shock. Vasopressor treatment, SAPS II score, serum creatinine on ICU admission and sepsis were the independent risk factors for development of any stage of AKI. Among the Stage 3 patients (34) 50% received renal replacement therapy. The overall utilization of intermittent renal replacement therapy was high (64.8%). The overall in-hospital mortality rate of AKI was 49% (55/112). The ICU mortality rate was 39.3% (44/112). The independent risk factors for ICU mortality were age, mechanical ventilation, SOFA score and AKI Stage 3.</p> <p>Conclusions</p> <p>For the first time we have established the incidence of AKI using the AKIN criteria in Hungarian ICUs. Results of the present study confirm that AKI has a high incidence and is associated with high ICU and in-hospital mortality.</p

Continuous central venous oxygen saturation assisted intraoperative hemodynamic management during major abdominal surgery: a randomized, controlled trial

Background: Major abdominal surgery is associated with significant risk of morbidity and mortality in the perioperative period. Optimising intraoperative fluid administration may result in improved outcomes. Our aim was to compare the effects of central venous pressure (CVP), and central venous oxygen saturation (ScvO2)-assisted fluid therapy on postoperative complications in patients undergoing high risk surgery. Methods: Patients undergoing elective major abdominal surgery were randomised into control and ScvO2 groups. The target level of mean arterial pressure (MAP) was≥60 mmHg in both groups. In cases of MAP2 group, in addition to the MAP, an ScvO2 of 3 % decrease indicated need for intervention, regardless of the actual MAP. Data are presented as mean±standard deviation or median (interquartile range). Results: We observed a lower number of patients with complications in the ScvO2 group compared to the control group, however it did not reach statistical significance (ScvO2 group: 10 vs. control group: 19; p=0.07). Patients in the ScvO2 group (n=38) received more colloids compared to the control group (n=41) [279(161) vs. 107(250) ml/h; p2 group received more blood transfusions (63 % vs. 37 %; p=0.018). More patients in the control group had a postoperative PaO2/FiO22 group (37/38 vs. 33/41 p=0.018). Conclusion: ScvO2-assisted intraoperative haemodynamic support provided some benefits, including significantly better postoperative oxygenation and 28 day survival rate, compared to CVP-assisted therapy without a significant effect on postoperative complications during major abdominal surgery. © 2015 Mikor et al.; licensee BioMed Central

Central Venous-to-Arterial CO2 Gap Is a Useful Parameter in Monitoring Hypovolemia-Caused Altered Oxygen Balance: Animal Study

Monitoring hypovolemia is an everyday challenge in critical care, with no consensus on the best indicator or what is the clinically relevant level of hypovolemia. The aim of this experiment was to determine how central venous oxygen saturation (ScvO2) and central venous-to-arterial carbon dioxide difference (CO2 gap) reflect hypovolemia-caused changes in the balance of oxygen delivery and consumption. Anesthetized, ventilated Vietnamese minipigs (n=10) were given a bolus followed by a continuous infusion of furosemide. At baseline and then in five stages hemodynamic, microcirculatory measurements and blood gas analysis were performed. Oxygen extraction increased significantly, which was accompanied by a significant drop in ScvO2 and a significant increase in CO2 gap. There was a significant negative correlation between oxygen extraction and ScvO2 and significant positive correlation between oxygen extraction and CO2 gap. Taking ScvO26 mmHg values together to predict an oxygen extraction >30%, the positive predictive value is 100%; negative predicted value is 72%. Microcirculatory parameters, capillary perfusion rate and red blood cell velocity, decreased significantly over time. Similar changes were not observed in the sham group. Our data suggest that ScvO26 mmHg can be complementary tools in detecting hypovolemia-caused imbalance of oxygen extraction

Hemodynamic effects of isovolemic anemia. These data have been published earlier [12].

<p>Hb- Hemoglobin, HR- Heart rate, MAP- Mean arterial pressure, CVP- Central venous pressure, CI- Cardiac index, GEDI- Global end-diastolic volume index, ELWI- extravascular lung water index, dPmx- Index of left ventricular contractility. T₀- Baseline measurement, T₁-T₅- Five intervals of bleeding.</p><p>*p<.05 compared with T₀; ^#p<.05 compared with previous; GLM repeated measures ANOVA.</p

Descriptives (Median±IQR).

<p>_cvCO₂-gap: central venous-to-arterial carbon dioxide difference; _vCO₂-gap: mixed venous-to-arterial carbon dioxide difference; P_(cv-a)CO₂/C_(a-cv)O₂: the central venous-to-arterial pCO₂ difference divided by the difference of the arterio-venous oxygen content; P_(v-a)CO₂/C_(a-v)O₂: the mixed venous-to-arterial pCO₂ difference divided by the difference of the arterio-venous oxygen content; ScvO₂: central venous oxygen saturation; SvO₂: mixed venous oxygen saturation; DO₂: oxygen delivery; VO₂: oxygen consumption; VO₂/DO₂: oxygen extraction ratio; ERO₂: simplified oxygen extraction ratio; PaCO₂: arterial partial pressure of carbon dioxide; PaO₂: arterial partial pressure of oxygen * p<.05 as compared to baseline, ^§ p<.05 significant difference between mixed venous and central venous blood with Friedman and Wilcoxon tests, ^# Data published earlier <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0105148#pone.0105148-Kocsi1" target="_blank">[12]</a>.</p

Correlation between oxygen balance parameters and CO₂-gap.

<p>_cvCO₂-gap and VO₂/DO₂ and ScvO₂ (on the left); _vCO₂-gap and VO₂/DO₂ and ScvO₂ (on the right). cvCO₂-gap: central venous-to-arterial carbon dioxide difference; VO₂/DO₂: oxygen extraction ratio; ScvO₂: central venous oxygen saturation; vCO₂-gap: mixed venous-to-arterial carbon dioxide difference.</p

The association between VO₂/DO₂ and ScvO₂. VO₂/DO₂: oxygen extraction ratio; ScvO₂: central venous oxygen saturation.

<p>The association between VO₂/DO₂ and ScvO₂. VO₂/DO₂: oxygen extraction ratio; ScvO₂: central venous oxygen saturation.</p